Parameters optimization design for LCL-type STATCOMs under complex power grid

Wang, Xiangyu,Wang, Minglei,Wang, Liguo,Fu, Guangjie,Qiao, Jinxin The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.2

LCL filter parameters and control parameters are interdependent and inter-restricted. They can all affect the stability of a static synchronous compensator (STATCOM) under the effects of a complex power grid such as harmonic grid voltage and grid impedance variation. An advanced parameters optimization method integrated with LCL filter and control strategy is proposed. At first, the ABC-Pareto algorithm (Pareto multi-objective optimization of an artificial bee colony algorithm) is used to reasonably choose the LCL filter parameters. Under the premise of using capacitor current feedback active damping control and grid voltage feedforward control, the mathematical models of the STATCOM are derived. The constraints of control performances on the control parameters are obtained. According to these constraints, it is possible to construct a satisfactory 3D space. The control parameters can be chosen reasonably by finding the optimized space when the power grid is changed. Simulation and experimental results show the effectiveness and superiority of the proposed method.

Geochemistry of the Early Cretaceous saline lacustrine shales on the Lingshan Island, East China: implications for provenance, tectonic setting, and paleoweathering

Xiangyu Zhang,Lu Liu,Qiang Sun,Yanming Xu,Shoujun Li,Xiaoli Wang,Xuxue Wang,Ying Sun,Wenxia Wang 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.4

Early Cretaceous saline lacustrine black shales in the Fajiaying Formation were deposited under hothouse conditions and have a complex structure and history of sedimentary evolution. In this study, integrated petrographic and geochemical investigations were utilized to determine the provenance, tectonic setting, and paleoweathering conditions of these shales, therefore revealing their depositional history. Shale in the area under investigation has not been subjected to any post-depositional alteration, mechanical sorting, or recycling, hence its geochemistry has not been affected. The chondrite normalized rare earth elements (REE) pattern of shales displayed typical characteristics, including an enrichment in light REE (LREE), a flat pattern for heavy REE (HREE), and a negative europium (Eu) anomaly. Specific trace element ratios suggested that the sediments were primarily derived from felsic source rocks. Furthermore, there was no discernible shift in the sediment source between the Qiancengya and the Laohuzui sections. The discrimination diagrams of major and trace elements used to understand the tectonic history showed that the majority of the source rocks originated from the active continental margin (ACM) and continental island-arc (CIArc). The bivariate plots and low average values of CIW (chemical index of weathering) and CIA (chemical index of alteration) for the examined shale suggested that chemical weathering in the source terrain under arid conditions was extremely weak. Importantly, with the change of climate from dry-hot to warmhumid, an increase in CIA and CIW was observed which indicated a gradual increase in chemical weathering.

Fabrication and Magnetic Properties of A New Fe-based Amorphous Compound Powder Cores

Xiangyue Wang,Deren Li,Caowei Lu,Feng Guo,Zhichao Lu,Shaoxiong Zhou 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

Fabrication and Magnetic Properties of A New Fe-based Amorphous Compound Powder Cores

Wang Xiangyue,Guo Feng,Lu Caowei,Lu Zhichao,Li Deren,Zhou Shaoxiong 한국자기학회 2011 Journal of Magnetics Vol.16 No.3

A new Fe-based amorphous compound powder was prepared from Fe-Si-B amorphous powder by crushing amorphous ribbons as the first magnetic component and Fe-Cr-Mo metallic glassy powder by water atomization as the second magnetic component. Subsequently by adding organic and inorganic binders to the compound powder and cold pressing, the new Fe-based amorphous compound powder cores were fabricated. This new Fe-based amorphous compound powder cores combine the superior DC-Bias properties and the excellent core loss. The core loss of 500 ㎾/㎥ at Bm = 0.1T and f = 100 ㎑ was obtained When the mass ratio of FeSiB/FeCrMo equals 3:2, and meanwhile the DC-bias properties of the new Fe-based amorphous compound powder cores just decreased by 10% compared with that of the FeSiB powder cores. In addition, with the increasing of the content of the FeCrMo metallic glassy powder, the core loss tends to decrease.

双碳背景下绿色金融对农业碳排放的影响研究

王星雨(Xingyu Wang),王翔宇(Xiangyu Wang),王晗(Han Wang) YIXIN 출판사 2023 Journal of China Studies Vol.1 No.5

经济全球化及“双碳”政策深入推进下,我国更加注重生态文明建设,逐渐加大农业绿色发展力度,已经初步获得良好的发展成效。不过农业发展中,在生态环境治理方面,仍面临较大挑战,应借助更多的方式,更好地实现农业绿色发展目标。对于绿色金融而言,其属于一种金融工具以及政策手段,能够有效提升农业生产效率,并且在农业碳排放控制上发挥着重要作用。基于此,本文简要探讨了绿色金融与农业碳排放相关内容,对绿色金融和农业碳排放现状予以分析,阐述绿色金融对农业碳排放的影响,并针对性地提出了双碳背景下绿色金融降低农业碳减排的相关政策建议,以期为农业碳减排目标的实现提供助力。 Under the deepening of economic globalization and the “dual-carbon”policy, China has paid more attention to the construction of an ecological civilization and has gradually increased its efforts in the green development of agriculture, which has initially gained good development results. However, in agricultural development, in the ecological environment management, still face greater challenges, should use more ways to better achieve the goal of green development of agriculture. For green finance, it belongs to a financial tool and policy instruments, can effectively enhance the efficiency of agricultural production, and play an important role in the control of agricultural carbon emissions. Based on this, this paper briefly discusses the green finance and agricultural carbon emission related content, analyzes the status quo of green finance and agricultural carbon emission, explains the impact of green finance on agricultural carbon emission, and puts forward the relevant policy recommendations of green finance to reduce agricultural carbon emission in the context of dual-carbon, with a view to providing assistance for the realization of the goal of agricultural carbon emission reduction.

An Improved Artificial Bee Colony Algorithm and Its Application

Xiangyu Kong,Sanyang Liu,Zhen Wang 보안공학연구지원센터(IJSIP) 2013 International Journal of Signal Processing, Image Vol.6 No.6

Mechanism of Synergetic Growth of Flexibility and Strength of Biomimetic Nanocomposite Fibre

Xiangyu Duan,Pan Li,Jingyu Ouyang,Zichen Gao,Jiaxin Liu,Jie Wang,Zhigang Xia,Weilin Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.3

Nanocomposites with carbon nanotubes (CNTs) can combine the stiffness and multi-functionality of carbonnanotubes with the advantages of high toughness and processability of polymers giving rise to properties different from thatof general composites. However, when the content of CNTs increases gradually, the flexibility of the composite fibre canreduce. In this paper, we propose a simple method of softening the composite fibre via dimensional helical deformation offibre inner macromolecule bundles to avoid the deterioration of fibre flexibility. The theoretical simulations were conductedto predict proper helical deformations of the single fibre to increase fibre softness, followed by practical softening of thepolyvinylidene difluoride (PVDF)/CNTs composite by tensional twisting of the single fibres. The fibres with and withouttensional twisting were tested by Fourier-transformed infrared spectroscopy, scanning electron microscopy, X-ray diffractionand mechanical drawing. Results showed the reinforcement of the PVDF/multi-walled CNTs composite fibres (tensilestrength enhanced from 4.71 to 5.19 cN/dtex) with an evident softness reduction (initial modulus increased from 16.8 to20.52 cN/dtex) as the CNTs content increased from 0 to 1.5 wt%. After the tensional twisting, the initial modulus of thecomposite fibre was reduced by 62.5 % while the fibre strength remained reinforced because biomimetic helix formationimproved the internal structure deformation ability of the fibre.

Optimization of Double Gate Vertical Channel Tunneling Field Effect Transistor (DVTFET) withDielectric Sidewall

XIANGYU WANG,Wonhee Cho,Hyoung Won Baac,Dongsun Seo,Il Hwan Cho 대한전자공학회 2017 Journal of semiconductor technology and science Vol.17 No.2

In this paper, we propose a novel double gate vertical channel tunneling field effect transistor (DVTFET) with a dielectric sidewall and optimization characteristics. The dielectric sidewall is applied to the gate region to reduced ambipolar voltage (Vamb) and double gate structure is applied to improve on-current (ION) and subthreshold swing (SS). We discussed the fin width (WS), body doping concentration, sidewall width (Wside), drain and gate underlap distance (Xd), source doping distance (XS) and pocket doping length (XP) of DVTFET. Each of device performance is investigated with various device parameter variations. To maximize device performance, we apply the optimum values obtained in the above discussion of a optimization simulation. The optimum results are steep SS of 32.6 mV/dec, high ION of 1.2× 10<SUP>-3</SUP> A/ μ m and low Vamb of -2.0 V.

JAS : JVM-Based Active Storage Framework for Object-based Storage Systems

Xiangyu Li,Shuibing He,Xianbin Xu,Yang Wang 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.7

We propose JAS, a JVM-based active storage framework for object-based storage systems. JAS programs the active storage functions of users as Java codes, and allows them to be executed on different OSD platforms (Operating systems and hardware) without recompiling. JAS offloads the active storage code from a client to the OSD by extending the standard OSD command set, and execute the Java code on the OSD on-demand by triggering them through extended client interfaces. We have implemented JAS under an object-based storage system. Experimental results show that the JVM-based active storage framework has been successfully set up, and this cross-platform design can largely improve system performance.

A Distributed Implementation Algorithm for Physical Layer Security Based on Untrusted Relay Cooperation and Artificial Noise

Xiangyu Li,Xueming Wang,Xiangyang Xu,Liang Jin 한국전자통신연구원 2014 ETRI Journal Vol.36 No.1

In this letter, we consider a cooperation system with multipleuntrusted relays (URs). To keep the transmitted informationconfidential, we obtain joint channel characteristics (JCCs)through combining the channels from the source to thedestination. Then, in the null space of the JCCs, jammersconstruct artificial noise to confuse URs when the source nodebroadcasts its data. Through a distributed implementationalgorithm, the weight of each node can be obtained from itsown channel state information. Simulation results show thathigh-level security of the system can be achieved when internaland external eavesdroppers coexist.